1. Field of the Invention
The present invention relates to a light emitting diode, and more particularly, to an AC light emitting diode capable of being operably connected directly to an AC power source.
2. Discussion of the Background
Light emitting diodes are an electroluminescence device having a structure in which n-type and p-type semiconductors are joined together, and emit predetermined light through recombination of electrons and holes. Such light emitting diodes have been used as display devices and backlights. Further, since the light emitting diodes have less electric power consumption and a longer life span as compared with conventional light bulbs or fluorescent lamps, their application areas have been expanded to the use thereof for general illumination while substituting for the conventional incandescent bulbs and fluorescent lamps.
A light emitting diode is repeatedly turned on/off depending on a direction of a current under AC power source. Thus, when a light emitting diode is used while connected directly to an AC power source, it cannot continuously emit light and may be easily damaged due to reverse current. Further, such a light emitting diode cannot be used while connected directly to a general AC power source, due to low operating voltage.
To solve such a problem of the light emitting diode, a method of positioning a rectifier between a light emitting diode and an AC power source to rectify AC current into DC current and then to operate the light emitting diode may be employed. However, the necessity of such a rectifier makes it difficult to substitute a light emitting diode for a lighting system such as a fluorescent lamp. Further, a method of connecting a plurality of light emitting diodes in reverse parallel with one another to connect the diodes directly to a high-voltage AC power source may be employed. However, since a large number of light emitting diodes should be operated while connected with one another, the overall size of a light emitting device is increased. Further, the number of processes such as wire connection is increased, because the light emitting diodes should be connected with one another.